As the integrated circuit industry has been developed according to Moore's law, feature sizes of CMOS devices are continuously scaled down, planar bulk silicon CMOS device structures are now facing severe challenges. In order to overcome these problems, various new device structures have been invented; among these new device structures, Fin Field-Effect Transistor (FinFETs) has been regarded as one of the new structure devices that will most probably replace bulk silicon CMOS devices, and therefore is under hot research nowadays all over the world.
FinFET structure devices were manufactured on SOI substrates in early time, and the manufacturing process thereof is much simpler than processes dealing with bulk silicon substrates. However, SOI FinFETs still suffer from many shortcomings like high manufacturing cost, poor heat dissipation, floating body effects and poor compatibility with CMOS process. In order to overcome aforesaid problems in SOI FinFETs, researchers begin research of manufacturing FinFET devices on bulk silicon substrates, i.e. bulk silicon FinFET. Nonetheless, as compared to SOI FinFET devices, the ordinary bulk silicon FinFET structure devices still have following defects: short channel effects (SCE) have not been suppressed desirably; current leaking path would still form in fin at channel bottoms so as to cause obvious current leakage; and doping profile cannot be controlled easily.
In order to overcome abovementioned problems and to boost application of FinFET structure devices as soon as possible, further research in said area has to be done, because this is of great significance to both application of FinFET structure devices and development of semiconductor industry.